Vacuuming and sealing devices for packaging



Jan. 12, 1965 F. J. PANCRATZ 3,164,934

VACUUMING AND SEALING DEVICES FOR PACKAGING Filed Oct. 5, 1962 INVENTOR; fiazz JPazzcra Z2 United States Patent F 3,164,934 VACUUMING AND SEALTNG DEVKIES FOR PAQKAGHNG Frank I. Pancratz, 924- S. Washington St., Park Ridge, Ill. Filed Oct. 5,1952, Ser. No. 228,7tl1 14 Claims. (Cl. 53-112) My invention relates to the packaging of food products in a vacuum, and more particularly to means suitable for application to containers of plastic material, such as cellophane. Methods now in use for this purpose involve a slow process of air withdrawal. Also, machines employed for this purpose are quite complicated, costly and slow in production, creating a high cost per package.

In order to depart from the above disadvantages, it is one object of the present invention to provide a quick method of vacuuming and a sealing device which is highly efficient toward maintaining a suitable vacuum and lending the package a good appearance after the final sealing operation.

A further object is to provide an exhausting device which employs flexible parts in connection with rigid ones in order to obtain a vacuum, using an assembly of formers, sealers and clamps.

Another object is to provide a device of the above character which is compact in size and direct in action.

A better understanding of the invention may be had by reference to the accompanying drawing, in which FIG. 1 is a top plan View of the device, showing its application;

FIG. 2 is a vertical section of the parts before the package is sealed;

FIG. 3 is a similar view, after the package has been sealed; and

FIGS. 4 and 5 are sections on the lines 44 and 55 of FIG. 2, the latter figure being on a reduced scale.

Referring specifically to the drawing, denotes a unit of the goods being packaged, such as a row of frankfurters. The container for them is composed of upper and lower sheets 12 and 13 of cellophane or'other plastic material which may be sealed together under heat. Suitable hot-press means may be employed to seal the side i and frontal portions 15 and 16 of the sheets together to form a container for the goods which is open at the rear as shown in FIG. 2. The mouth of the package, in the form seen in the center of FIG. 2, is designed to receive the novel vacuumizing and sealing device shown in section. FIG. 1 shows that the pre-sealed contour of the package continues part-way around the rear-as shown at.2l'so that the mouth of the package is of lesser width; and the same figure shows that the sealing assembly is of the same width in front, but wider at the rear.

The principal part of the exhausting unit is a metal housing 25 of tubular form and preferably circular in cross-section, as shown in FIG. 4. The housing carries a solid frame 27 around its frontend. The frame is extended in width to points 27a, this shape corresponding to that of the package mouth 12-13. A liner 28 of sheet rubber fits between the housing 25 and the frame 27, and tapers in forward direction to form a funnel 28a whose front end is folded back inwardly as seen at 2812 to fit snugly around a central tube 35.

The frame 27 and housing 25 are supported midway between upper and lower clamps 30, these being backed by springs 31; and cushion tubes 33 are carried by the clamps 30 to transmit their pressure to the container sheets 12-13 passing between the tubes and the frame 27.

The central tube 35 is the vacuum-transmitting element, such tube leading from a suitable vacuum source into the frontal funnel 28a of the liner 28 to open into the neck portion 12a of the container 12-13 as shown in FIG. 2. A rubber diaphragm 37 is located between the 3,164,334 Patented Jan. 12, 1955 tube 35 and the rear end of the housing, the frontal portion 37a of the diaphragm gripping the tube, and the rear portion being wrapped around the housing and held fast by a retainer ring 38. FIG. 2 shows the diaphragm telescoped in the housing. It is now apparent that the front and rear rubber attachments 28a and 37 between the housing and center tube form an air-tight chamber 40 around the tube.

When the parts are positioned as in FIG. 2, the device is ready for exhausting air from the food package. This is done from a vacuum source which is continuous or turned on when needed. When the desired amount of vacuum has been procured, the tube 35 is retracted to re verse the direction of the rubber elements 28a and 37, as seen in FIG. 3. This action holds the vacuum in the food package, and makes room for the co-acting application of the clamps 30 and formers 42-spring-backed as indicated at 42a-to flatten the neck portion 12a of the container 12-13. Now, spring-backed sealing bars 43- containing electric heating units 43a-meet as shown in FIG. 3 and seal the mouth of the package together. A suitable knifenot shown-is now applicable to cut the package off from the trailing sheets 12-13, in order that these may advance the distance of the arrow 19 in FIG. 1 to form the next container.

The application of the sealing bars 43 exerts a pressure on the sheets 12-13 toward their meeting zone with a slight forward pull. Allowance for this is made in the zones of the clamp-bars 30, so that they may yield in the 'forward direction from the vertical positions shown in FIG. 2 to the tilted ones indicated in FIG. 3. The tilt of the bars is resisted by cross springs 45, which act to restore the clamp-bars to the original positions after the food package has been completed from the sheet material 12-13.

The pull from the application of the sealing bars may also be extended to the housing 25 by Way of its funnel 28a. The housing will therefore advance a slight distance and pull on a spring 46 extending from a side lug 25a of the housing to a stationary element 47 located nearby. The spring of course restores the housing to the original position after the package completing operation.

It is noted in FIG. 1 that the clamp 30 is wider than the mouth of the package, the object being to prevent air leakage, and the width of the clamp depending on the kind of sheeting used for the package. The sheets 12-13 are clamped between the smooth surface of the frame 27 and around the rubber tubes 33 carried by the clamp 30 in order to form an air-tight container for the product It).

One or more exhausting units may be used for the container, such unit or units being movable to the side of the container to facilitate loading of the product 10 into the container sheets 12-13.

In practice the device operates as described when the sheet material 12-13 is of relatively heavy gauge. However, when the material is quite thin, it may have a tendency to come together in the zone of the funnel 28a from the influence of the vacuum. To counteract this, the chamber 40 is made more firm by inflation to a suitable pressure by way .of a check valve 50. The return fold 28b facilitates the peeling of the funnel 2811 from the interior of the package sheets 12-13 as the tube 35 is being withdrawn, in order to avoid leakage. Also, the peeling operation protects the sheets from tearing or deforming. This operation is so eflicient that the use of a funnel of heavy gauge will make it unnecessary to provide the diaphragm 37 in the rear of the housing 25.

The clamps 30, formers 42 and sealing bars 43 are 017- erated by upper and lower dies or presses 18 which are gathered by suitable means from the positions in FIG. 2 to those in FIG. 3. Each die carries a headpiece 13a supporting the clamps, formers and sealing bars. The

clamps, formers and side sealers are the first to form an air-tight container, while the formers 42 are the first to engage the package mouth as the dies gather, the sealers engaging the same next, as shown in FIG. 3, to close the mouth of the package hermetically by heat-pressure. Sealing of the container is done during exhaustion and the final sealing period.

It is the additional function of the formers to bar heat radiating from the sealers and impose a chilling line in the package adjacent to the sealed region. The formers also combine to act as a stripper. When the dies are apart, the units carried by them are in positions to form a clearance for the insertion of the package sheets and exhausting assembly; and a cross-pin 51 is carried in each headpiece as a stop for the separation of such units. It is also possible to close the mouth of the package by means of a die on one side--operating a set of clamps, formers and sealing bars-and a stationary support or platen on the other side.

It is now apparent that the parts making up the novel sealing device are concentrated in and close to the feeding zone of the food package, making the assembly compact. Further, the association of sealed and flexible end portions with the vacuum feed enables the exhausting, closing and sealing of the food package to be accomplished without leakage. Finally, the parts entering into the construction of the device are few and simple in character.

I claim:

1. Vacuumized closing apparatus for the mouth of a package formed with companion sheets sealed together at the sides, comprising a tubular housing opening with one end into said mouth, a tube leading from a vacuum source into the housing and adapted to be advanced into said mouth a distance beyond said end, a flexible sheet extended in air-tight relation between said end and the corresponding end portion of the tube, said flexible sheet being funnel-shaped to seat closely between the package sheets, means supplementing the housing laterally to fill said mouth where the package sheets join at the sides, the tube being retractable to roll the flexible sheet back out of said mouth without loss of vacuum, and means then operable to secure the package sheets together where they form said mouth.

2. The structure of claim 1, and a second flexible sheet extended in air-tight relation between another portion of the housing and said tube to form a sealed chamber around the latter.

3. The structure of claim 1, a second flexible sheet extended in air-tight relation between another portion of the housing and said tube to form a sealed chamber around the latter, and means for charging the chamber with a compressed medium in order to fortify said flexible sheets against collapsing influences of said vacuum.

4. The structure of claim 1, said flexible sheet being connected to the tube with a return infold as a lead for the rolling action of the sheet.

5. The structure of claim 1, the first named means being a frame with an opening receiving said end, and the larger end of the flexible sheet seating between said end of the housing and the rim of said opening.

6. The structure of claim 1, the first-named means being a frame with an opening receiving said end, the larger end of the flexible sheet seating between said end of the housing and the rim of said opening, and clamps applicable to the frame from opposite sides.

7. The structure of claim 1, the first-named means being a frame with an opening receiving said end, the larger end of the flexible sheet seating between said end of the housing and the rim of said opening, and springbacked clamps applicable to the frame from opposite sides.

8. The structure of claim 1, the first-named means being a frame with an opening receiving said end, the larger end of the flexible sheet seating between said end of the'housing and the rim of said opening, clamps applicable to the frame from opposite sides, and yieldable inserts between the clamps and the frame.

9. The structure of claim 1, and clamps applicable to the frame from opposite sides, said clamps being yieldable laterally in response to pulling strains when the package sheets are secured together as stated.

10. The structure of claim 1, the housing having a slight yieldable factor in response to pulling strains when the package sheets are secured together as stated.

11. The structure of claim 1, the last-named means comprising heated sealing bars directed to the sheets from at least one side.

12. The structure of claim 1, the last-named means comprising heated sealing bars directed to the sheets from opposite sides, and formers directed similarly and effective as strippers and to form a chilling area alongside the sealing course.

13. The structure of claim 1, a die on each side of the sheet group, a headpiece carried by each die, and clamping, heat-sealing and forming units carried by each die, the gathering of the dies applying said units to secure the package sheets as stated.

14. A vacuumizing and sealing unit for closing the mouth of a food package in air-tight condition, such mouth composed of scalable sheeting, comprising a pair of concentrically related members of tubular form, the inner member connected at one end to a vacuum source and extending with the other end beyond the outer member into said mouth, a flexible connector between the members formed to be engaged closely by said mouth, and a second flexible connector between the members, the connectors combining with the members to form a chamber suitable to receive a compressed medium for stiffening the first mentioned connector to resist collapsing influences on said mouth from said vacuum.

No references cited. 

1. VACUUMIZED CLOSING APPARATUS FOR THE MOUTH OF A PACKAGE FORMED WITH COMPANION SHEETS SEALED TOGETHER AT THE SIDES, COMPRISING A TUBULAR HOUSING OPENING WITH ONE END INTO SAID MOUTH, A TUBE LEADING FROM A VACUUM SOURCE INTO THE HOUSING AND ADAPTED TO BE ADVANCED INTO SAID MOUTH A DISTANCE BEYOND SAID END, A FLEXIBLE SHEET EXTENDED IN AIR-TIGHT RELATION BETWEEN SAID END AND THE CORRESPONDING END PORTION OF THE TUBE, SAID FLEXIBLE SHEET BEING FUNNEL-SHAPED TO SEAT CLOSELY BETWEEN THE PACKAGE SHEETS, MEANS SUPPLEMENTING THE HOUSING LATERALLY TO FILL SAID MOUTH WHERE THE PACKAGE SHEETS JOIN AT THE SIDES, 